Physics - October 2006

2006-10-05 15:58:51 · 5 answers · asked by keran_guy 2

A 2-kg block sits on an incline where the top part of the incline has a coefficient of friction of kinetic friction of 0.70. The bottom section of the plane has kinetic friction of 0.95. THe angle of inclination is 40 degrees. The block is released and travels 10 m along the initial part of the incline and then enters the lower section. Calculate how far the block travels along the second section before it is brought to a stop.

I only want to know how to do it, because i don't know how to set it up. Please help me figure this out.

2006-10-05 15:34:53 · 2 answers · asked by Anonymous

Explain 'burning mirrors' concept of Archimedem's time.
Explain & demonstrate how this could have worked.

2006-10-05 15:30:54 · 4 answers · asked by zzangga 1

Gallium at room temp is liquid Water expands when frozen.

If gallium is kept from expanding as it becomes solid at a real low temp what would happen?

2006-10-05 15:27:26 · 2 answers · asked by Buzz and Gang 2

Two crates, of mass m1 = 70 kg and m2 = 115 kg, are in contact and at rest on a horizontal surface (Fig. 4-54). A 620 N force is exerted on the 70 kg crate. The coefficient of kinetic friction is 0.15.

Calculate the force that each crate exerts on the other.

2006-10-05 15:00:36 · 2 answers · asked by Diane W 1

I don't have an answer to this one, just looking for the correct one, with proof if possible.

Question again:

A golf ball is hit with a force of 50 Newton's, disregarding air resistence, and assuming all other quantities are constant, what angle should the ball be hit at to yeild maximum length? Height?

Thanks.

2006-10-05 14:53:02 · 6 answers · asked by Anonymous

I dont understand why a mirror reflects everything

2006-10-05 14:39:35 · 11 answers · asked by Anonymous

A rod of length L is place in a bowl with radius r, find angle O for equilibrium (the rod make with the horizontal, which is across the mouth of the bowl) . Express answer in term of L and r.

2006-10-05 14:38:55 · 4 answers · asked by Henry T 1

this one has me stuck with the whole vacuum thing. is it 19.6? or zero? help!

2006-10-05 14:25:24 · 3 answers · asked by <333 3

2006-10-05 14:24:41 · 4 answers · asked by tootsiebaby214 1

2006-10-05 14:01:18 · 5 answers · asked by mailmetlc 3

Josie and Charlotte push a 12-kg bag of playground sand for a sandbox on a frictionless, horizontal, wet polyvinyl surface with a constant, horizontal force for a distance of 5 m, starting from rest. If the final speed of the sand bag is 0.3 m/s, what is the magnitude of the force with which they pushed?

2006-10-05 12:38:37 · 2 answers · asked by Anonymous

i have a test tom. and still a little confused.
i have that net force causes acceleration, finding total of vectors. if object moving at constant velocitythen tere's no net force
normal force holds an object to the surface. it always acts perpindicular to surface. Normal for for an object on flat horizantal surface is the weight of that object.

is there anything else i'm missing. Are the things above right?
Thanks

2006-10-05 12:24:56 · 3 answers · asked by Anonymous

why the pressure inside a tank decreases as air is released

2006-10-05 12:14:43 · 3 answers · asked by audaciously_shy 2

A friend of mine recently brought me a touch sensitive light, it's fun to play with but it bugs me that I don't quite understand how it works. My best guess is that by touching the metal part I am interfering with a magnetic field and it's by monitoring that field that the lamp knows if its been touched. Does that sound plausible to the physicists out there? If that isn't right, how does it work?

2006-10-05 12:03:12 · 15 answers · asked by alexjcharlton 3

choices are... 100, 10.8, 108, 180 ???

2006-10-05 11:23:15 · 5 answers · asked by hmmm 1

Elite major league fireballers generally top out at about 100-101 mph, although a few have been clocked at 103 mph in a game. Getting a little theoretical, what is the physical limit on the speed of a pitch by a player? Realistically could a player throw 150 mph without dismantling their shoulder, or is about 103 mph the fastest we'll see in our lifetime?

2006-10-05 11:20:22 · 2 answers · asked by ? 3

2006-10-05 11:15:16 · 10 answers · asked by Anonymous

2006-10-05 11:14:04 · 5 answers · asked by Anonymous

a stone is thrown vertically upward with a speed of 12 m/s from the edge of a cliff 75m high.

1) How much later does it reach the bottom of the cliff?

2) What is its speed just before hitting?

3) What total distance did it travel?

im having so much trouble with this question, u have no idea! im hoping you guys can help me !

thnx for all of your help!

2006-10-05 11:12:42 · 3 answers · asked by Anonymous

it should utilise a lever an inclined plane a pulley and gears!

2006-10-05 11:06:36 · 1 answers · asked by Mrs. P Romeo Miller 1

2006-10-05 11:05:38 · 3 answers · asked by Jamaican Dime 1

Please assume you have just opened the can.

2006-10-05 11:03:27 · 4 answers · asked by Knobbie 3

2006-10-05 11:01:17 · 11 answers · asked by rvn 1

A Big Rig can tow 80,000 Lb and it takes approximately 26-28,000 Lbs of force to stop it from taking off with brute force (assuming tires don't lose traction and its in 1st gear)- (100X the weight of a big guy) even though it can safely tow 400 of them

So, is that a lot of force?

2006-10-05 10:49:14 · 5 answers · asked by S--slick 4

over a rough surface by a constant force of 99.9 N acting at an angle of 29 degrees above the horizontal. You move the trunk over a distance of 79.3 m in a straight line.
The coefficient of kinetic friction is 0.111, and acceleration of gravity is 9.8 m/s^2.

How much is the work done on the block by the net force?? Answer in units of J.

2006-10-05 10:40:04 · 2 answers · asked by Anonymous

Think i asked that a bit wrongly.

2006-10-05 10:28:25 · 5 answers · asked by Nick n his Dog 2

A tiger leaps horizontally from a 12m high rock with a speed of 4.5m/s. How far from the base of the rock will she land?

and

A diver running 1.6 m/s dives out horizontally from the edge of a vertical cliff and reaches the water below at 3.0s later. How high ws the cliff and how far from its base did the diver hit the water?

Please show your work and explain to me how I can solve these two problems.

2006-10-05 10:22:42 · 2 answers · asked by hdwong58 3

On my last Physics test, there was a problem concerning a cannon firing a shell at 1200 m/s at 50 degrees from the horizontal. I was to find the horizontal distance the shell traveled. What I did is I broke the 1200 m/s into its vertical and horizontal components. Then I used those numbers to figure out how long the shell would be in the air, and used that to figure out how far away the shell would be when it landed. I got the question right.

But, I'm pretty sure there's a serious difference in the answer when you stop assuming that the earth is flat. What I'd like you nifty physics experts to do is take into account the curvature of the earth and the lessened strength of gravity when far away for the earth's surface (you can continue to ignore air resistance). Did the shell clear the earth's pull entirely? Is it in orbit? Did it finally hit the other side of the earth?

What's the real answer to my test question?

2006-10-05 10:18:16 · 5 answers · asked by Mehoo 3

2006-10-05 10:03:44 · 21 answers · asked by Nick n his Dog 2